186 RESEARCHES ON IRRITABILITY OF PLANTS 



distance on the stem, the transmission period could be made 

 as long as desired. This will be seen in fig. 101, where 

 thermal stimulus was applied on the stem of Mimosa at 



Fig. ioi. — Positive response, preceding the negative in Mimosa. 

 Stimulus was applied on the stem. Frequency of oscilla- 

 tion i per second. 



some distance from the pulvinus. The record was taken 

 on a slowly moving plate, by means of the Oscillating 

 Recorder, the successive dots being made at intervals of a 



Table III. — Periods of Transmission of Positive and Negative 

 Impulses in the Petiole of Averrhoa and Stem of Mimosa 



